Portable power supply



FIG. 1 is a perspective view of a portable power supply showing our new design;

FIG. 2 is a top view of the portable power supply shown in FIG. 1;

FIG. 3 is a front view of the portable power supply shown in FIG. 1;

FIG. 4 is a rear view of the portable power supply shown in FIG. 1;

FIG. 5 is a bottom view of the portable power supply shown in FIG. 1;

FIG. 6 is a left-hand side view of the portable power supply shown in FIG. 1; and,

FIG. 7 is a right-hand side view of the portable power supply shown in FIG. 1. 

The ornamental design for a portable power supply, as shown and described. 